Gas-insulated circuit breakers are design to interrupt an current by separating two contacts in an dielectric gas, such as sulfur hexafluoride (SF6), having excellent dielectric and arc-quenching properties. The dielectric gas can be contained in a housing. A nominal contact system and an interruption contact system can be provided in the housing. The nominal contact system can include nominal contacts and can selectively establish a rated current path, i.e. a rated current can be conducted by the nominal contact system. The interruption contact system can include a pin and a tulip can selectively establish a power current path. After separation of the interruption contact system an arc can be formed between the pin and the tulip and current can be carried through the arc.
During the separation the pin can be moved relative to the tulip at a considerably higher speed than the nominal contacts. Gas-insulated circuit breakers are commonly designed such that a damping of the separation movement is can be provided at the end of the separation movement. Typically, a compression volume is available to damp out the movement of the pin relative to the tulip.
There are gas-insulated circuit breakers, in which the damping is achieved by a compression volume provided around the pin. Structural and tightness requirements are guaranteed by a series of guiding and sealing rings. While this system may be effective, the high number of parts and the design is such that a high number of parts with extremely tight tolerances must be put in place. Additionally the usage of the volume around the pin as damping element require a rather lengthy pin implying a lengthy interrupting housing, pole frame and enclosure.
DE 10 2014 102929 A1 describes a circuit breaker having a gas damper for damping a movement of a pin. The gas damper is operatively coupled to the pin. Specifically, the pin or a piston coupled to the pin can be moved into the gas damper for damping the separation movement of the pin relative to the tulip.